#include "cv.h"
#include "highgui.h"

int main(){
	CvMat* mat = cvCreateMat(100,100,CV_8UC3);
	cvZero(mat);
	int i,j;
	for(i = 20;i < 40; ++i){
		for(j = 5;j < 20; ++j){
			uchar* p = cvPtr2D(mat,i,j);
			p[1] = 255;
		}
	}
	cvNamedWindow("drawRectangle",CV_WINDOW_AUTOSIZE);
	cvShowImage("drawRectangle",mat);
	cvWaitKey(0);
	cvDestroyWindow("drawRectangle");
}